The Community Child Health Network (CCHN) Phase II research proposes to: (1) advance understanding of the combined biomedical, social, behavioral, and environmental influences on the course of prenatal development, pregnancy outcome, and early child development, particularly in physical growth, respiratory function, and language development. CCHN proposes a 5-site, longitudinal study of 2 integrated cohorts: a Birth Cohort Study of 5250 families (1050 per site)) followed by a Subsequent Birth Study (38 percent of mothers expected to have a subsequent live birth). These studies focus on the role of stress and allostatic load, as moderated by resilience and supports, on pregnancy outcome, fetal programming, and child development outcomes of prematurity/intrauterine growth restriction, overweight, asthma, and language and cognitive development;and (2) to develop and document active community participation in all phases of the study through the community based participatory research (CBPR) in the community-academic partnerships (CAPs). The findings are intended to advance theory about the etiology and impact of health disparities related to pregnancy and early childhood outcomes, as well as inform the design of future preventive interventions. Innovative features include: 1) focus on the inter- and pre-conception period;2) combining biomedical and psychosocial indicators and outcomes within an integrated conceptual framework;3) multidisciplinary measures of resilience and supports as well as risks;4) including fathers as integral to both pregnancy and child health outcomes;and 5) a participatory research partnership of the community and university at local sites and the national network. CCHN-Lake County, IL is comprised of academic partners Evanston Northwestern Healthcare, its academic affiliate Northwestern University and its community partner, the Lake County Health Department Community Health Center. In phase 1, these partners have facilitated the development of a Community Advisory Committee (CAC) focused on improving the lives of young families in Lake County. CCHN-Lake County, IL has major strengths in population representative study design and analysis, longitudinal studies in the field, and field-based biomarker collection and assessment. Content strengths include pediatric health disparities, the fetal origins of adult disease, culture and health, the father's role in child health and development, caregiver stress and childhood chronic disease and the relationships among select biomarkers and family dynamics. CCHN-Lake County, IL will enroll and follow 1050 families (25 percent African American, 55 percent Latina, 20 percent non-Hispanic White, and 80 percent low income) based on a representative sample of Illinois births to Lake County women.